Israeli authorities in Jerusalem today handed the Irgun Zvai Leumi an ultimatum to liquidate itself as an independent organization and demanded that all its members immediately enlist in the Israeli Army, without attaching any conditions to their service. This is the latest in a series of antiterrorist activities initiated by the government in the wake of the assassination in Jerusalem last Friday of U.N. mediator Count Folke Bernadotte and his French aide, Col. Andre Serot.

An Irgun spokesman in Tel Aviv tonight said that the members of the organization are embittered by the ultimatum, since an agreement had almost been reached with the government on that issue. However, the spokesman said, the Irgun will accept the ultimatum and will offer no opposition.

Even as the first public announcements of the details of the government’s anti-terrorist regulations were being made, it was learned that a large detention camp has been prepared for terrorists apprehended under the new emergency legislation. The measures, which incorporate many of the features of the British administration’s Emergency Defense Regulations, do not provide for capital punishment. Ordinary crimes, such as murder, will continue to be handled under the regular legal code.

ANTI-TERRORIST DECREE PROVIDES FOR 5 TO 20 YEARS IMPRISONMENT

The draft regulations, already approved by the Cabinet, and signed tonight by David Ben Gurion, Premier and Defense Minister, provide for five to twenty years imprisonment for participating in acts of terrorism, while prison sentence of one to five years are provided for membership in terrorist organizations. A fine of $4,000 or imprisonment up to three years, or both, was set for aiding or abetting such organizations. Violators of the anti-terrorist statutes will be tried by military courts.

In official quarters it was stated that the laws place an “effective instrument” in the hands of the government for purposes of eradicating terrorist organizations. The measures will not only permit the government to proceed against terrorist groups, it was pointed out, but will also define exactly what constitutes such a group.

Meanwhile, it is reported that police and military dragnets, which extend even to-checking and halting traffic between Jerusalem and the rest of Palestine, have not yet uncovered the whereabouts of major Sternist leaders, including Nathan Friedman-Yellin and a Dr. Sheiber, commander and deputy commander, respectively, of the Stern Group organization. Among the important witnesses questioned by the authorities are a group of children who spoke with the assassins while they waited for Bernadotte’s convoy to appear.

Sternist circle today revealed that the Fatherland Front, which has accepted responsibility for the murders, two weeks ago split away from the parent organization when its members refused to accept the discipline of the central committee which had decided to cease terrorist activities and become a legal party. The assassination was planned within a week, these same circles said.

At a press conference last night, Menahem Beigin, Irgun leader, called the emergency measures undemocratic, adding that “this is not the time for mass arrests, secret police and concentration camps.” Beigin paid tribute to the memory of the slain U.N. mediator and expressed his sympathy to the Count’s family. He asserted that there is no connection between the Irgun and the Fatherland Front. Beigin stated he was appalled at the assassination and wants the culprits brought to justice, but declared that nevertheless the “government of Israel does not have the right to arrest people just because they belong, or used to belong, to an opposition party.”